Quantifying the trade-off between percentage of renewable supply and affordability in Pacific island countries: Case study of Samoa

Pacific island countries are particularly susceptible to sea level rise as a result of climate change and also face high costs and energy security issues from imported fossil fuels. As a result many Pacific island countries are perusing 100% renewable energy targets. Due to challenges with variable renewable energy sources, detailed studies that balance renewable energy supply and demand at a fine temporal scale have been carried out for many countries to inform policy directions. Despite having adopted renewable energy targets, most Pacific island countries have not been subject to the same level of detailed analysis in the academic literature. In addition, the results from other countries are not directly applicable given the particular local resources, climatic conditions and economic situation of Pacific island countries. In this paper, focusing on the case of Samoa, we use an approach based on historical electricity demand and generation time-series data to investigate future scenarios that achieve very high percentages of renewable electricity. The results show that scenarios of high proportions (above 90%) of renewable energy generation coupled with storage (28%–37% of direct solar, 17%–30% of stored solar and 25%–40% of hydro) are economically viable (Net Present Value >0) but, there is a significant trade-off between percentage of renewable supply and affordability. These results have important implications for energy policy directions for Samoa and are directly applicable to many other countries in the Pacific.